Metaphorically each rich nation can be seen as a lifeboat.... In the ocean outside each lifeboat swim the poor of the world.... What should the lifeboat passengers do? ... Suppose the 50 of us in the lifeboat see 100 others swimming in the water outside, begging for admission to our boat.... We could take them all into our boat, making a total of 150 in a boat designed for 60. The boat swamps, everyone drowns. Complete justice, complete catastrophe.

That way of looking at immigration, penned by the late ecologist Garrett Hardin in 1974, is no doubt too alarmist. But part of me fears that Hardin may be partly right—that in the long run, the massive legal and illegal immigration of the world's poor, huddled masses will swamp our nation's prosperity. Immigration has already depressed the wages and job opportunities of low-income native-born Americans. The notion that immigrants fill "jobs that Americans don't want" is a cop-out that flies in the face of economic reality. The reason Americans in some areas won't take jobs washing dishes, cleaning hotel rooms, mowing lawns, and picking fruit is that immigrant labor has driven the wages down, as the liberal Harvard sociologist Christopher Jencks demonstrated two years ago in The New York Review of Books.

But while Hardin would have been horrified by President Bush's January 7 proposal to move toward a more generous policy on illegal immigration, I think it's a good start.

How to reconcile these seemingly conflicting thoughts? Begin by recognizing what no politician can safely acknowledge: The inescapable choice, at least in the short run, is between cruelty to poor would-be immigrants and cruelty to the poor native-born Americans. We have a moral duty to treat both groups with sympathy and compassion. But the more direct impact of immigration policy on those seeking to immigrate, and the disagreements among experts about whether and how much the current wave of immigration will help or hurt Americans in the long run, argue for a policy shaped by generosity rather than by possibly exaggerated fears.

The case for a generous approach is enhanced by recognition of the political impossibility of stemming the tide that is adding 200,000 to 500,000 new entrants a year to an illegal-immigrant population estimated to total 8 million to 14 million. The only way to stop the flow would be to completely militarize the Mexican border, require all Americans to display on demand a biometrically encoded national identification card, launch regular dragnets through barrios and workplaces, and engage in other police-state measures abhorrent to most Americans. While most voters want to cut down on illegal immigration, most would not support such draconian and constitutionally troublesome policies.

Consider the fate of the 1986 immigration reform act. Its purpose—other than giving amnesty to the millions of illegals already living in the U.S.—was to end the influx by using tough measures including tight border controls and penalties to deter employers from hiring illegals. But it failed abjectly: Despite huge increases in the Border Patrol's budget and number of officers—which have driven desperate Mexicans to border-crossing efforts so dangerous that one a day dies en route—the flow of illegals continued to soar. Meanwhile, Congress's refusal to adopt a national identity card and the government's lack of political will to enforce the employer sanctions doomed the reforms to ineffectiveness.

The political forces opposing tough measures to cut down immigration have grown stronger since 1986 because of the rising numbers and clout of pro-immigration Latinos, and because many labor leaders have shifted from opposing immigration—as did the late Cesar Chavez—to supporting it, the better to recruit as members people who will come to America one way or another.

Massive illegal immigration thus seems destined to continue unless and until Mexico and other poor countries become prosperous enough to keep their people. This is not to argue for ending all immigration restrictions or treating illegals with generosity as soon as they have successfully sneaked across the border. Doing that could launch a new tidal wave that would rapidly drive down wages, drive up unemployment, and make our overcrowded metropolises more and more like Mexico City and Tijuana.

The critical question for policy makers should be at what points along the spectrum of harshness the moral and practical costs of making life difficult for illegals come to outweigh the benefit of deterring them from coming and staying. Denying welfare benefits to recently arrived illegals, for example, seems a logical way to avoid becoming a magnet for immigrants seeking handouts. Barring illegal immigrants from public schools, on the other hand, seems repugnant both because it would condemn innocent children to lifelong membership in a growing, uneducated underclass in our midst—most are here to stay—and because it won't deter the vast numbers of would-be illegal immigrants who have no children.

Some conservatives justify a punitive approach by stigmatizing illegal immigrants as lawbreakers who should be treated harshly in fairness to the millions of others who wait overseas to qualify for legal immigration. This cannot withstand analysis, in my view. Aside from a tiny minority of terrorists, smugglers, and criminals, most of those who violate immigration laws by sneaking across our borders deserve to be treated with dignity and respect—even if they must be deported to enforce the law.

Imagine a poor, unemployed Mexican whose brother sends word that he can get him a job picking fruit, if he can make it across the desert to California without getting caught or killed. Inspired by the same American dream as our ancestors, he comes and works long hours so that he can send money home to support his destitute family and make a better life in the land of opportunity. Would you fault him for breaking the law of a country that is happy to look the other way while he and millions of other illegals do its lowliest jobs? I wouldn't, any more than I would condemn a pain-racked patient for using medical marijuana to relieve his agony or a pedestrian for jaywalking to rush medicine to her sick child. And with all respect to those who wait to immigrate legally, I suspect that most do so not because of legal scruples but because they are in less desperate straits or more likely to be admitted.

Bush's guest-worker proposal strikes me as a step in the right direction because it is more generous to illegals than the status quo while seeming unlikely to touch off a massive new influx. It would allow those who have already immigrated illegally (and those who are prepared to do so)—if they have jobs or job offers—to live and work openly (and pay taxes) for at least six years. This would mean better chances of being promoted, labor-law protections, and opportunities to get driver's licenses, open bank accounts, and visit families at home without fear of being barred from returning. My speculation that these improved living conditions would not spur a large net increase in immigration is based on two premises: The new incentives for employers to hire guest workers would mean fewer jobs for illegals, and the pace of illegal immigration appears to be determined not by living conditions in the barrios but by the availability of jobs.

The glaring flaw in Bush's so-far-vague proposal is the lack of any clear-cut process for allowing guest workers to stay more than six years. This may help politically and prevent the proposal from becoming a magnet for more immigration. But if the final version appears to require all guest workers to leave after six years, people determined to stay will either shun the program or return to the shadows once their terms have run.

The challenge for Bush and Congress is to design demanding but achievable steps for guest workers to earn permanent residency and eventually citizenship, such as learning English, passing exams on our constitutional traditions and history, paying their taxes, avoiding trouble with the law, and keeping their children in school. The challenge for critics—who have identified many a problem with Bush's proposal, as could be done with any immigration proposal—is to come up with a better idea. The challenge for the rest of us, if a guest-worker program passes, will be to give those working to become Americans a sense of belonging—and give the lie to the identity-politics ideologues who will tell them they are victims of oppression by the white-dominated society that took them in.

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